A typical picture frame is designed to hang on a wall and usually has means to engage a hanger such as a nail or hook driven into the wall. The frame and a picture are usually assembled together from the back prior to mounting. Then, a hook, nail or other hanging device is attached to the wall at a desired location, usually chosen to be hidden behind the frame to maintain an aesthetic appearance. A wire for suspending the frame may be strung across the frame back to engage the hanging device. Otherwise, the frame may be fitted with one or more clips that slip fit onto one or more wall mounted hangers, as shown for example in U.S. Pat. No. 3,707,053.
The problems with these systems are that it is difficult to assure that a picture is at the correct height and level when placed on the wall and that it will remain level over time. With wire mounting, the frame may not remain flush with the wall and, through vibration, may slide on the wire. Also the degree of slack in the wire may cause the picture to hang too low or too high, requiring the hanging device to be pulled from the wall and repositioned. The difficulty with clips is that precise positioning is difficult, usually requiring several attempts at locating the wall mounted fasteners so these are both precisely level and at the correct location for engaging the frame mounted clips. These procedures take time and often results in multiple holes being placed in the wall.
In U.S. Pat. No. 5,230,172, a picture frame has means to mount pictures on opposite sides thereof, so that it can be free standing. Alternately, the frame can be wall mounted prior to receiving a picture and a face member. However, the problems with mounting and leveling the frame remain.
In U.S. Pat. No. 6,354,031, a device for displaying documents has a back panel attached to a wall, receiving a frame with a corresponding shaped recess thereover so that the frame can be mounted thereon and held in place by flexing elements.
In U.S. Pat. No. 5,353,536, a display assembly for signs or posters utilizes a similar rear member that is wall mounted, with a frame secured thereover that interlocks the frame and rear member together. A foam backing is used to compress a poster against a front surface of the frame.
None of these frame designs provide ease in mounting a picture frame to a wall with additional ease in precise frame leveling. The search thus continues for a picture frame assembly that is easy to level and mount to a wall, but also has the ability to change the picture, without removing the frame from the wall.